Gunther originally started out as a background character but due to a stroke of luck of knowing how to operate a cappuccino machine, he became one of the most memorable minor characters of the series.

He seems to be the manager (I guess) of Central Perk, the coffee shop that the main characters often hung out at. He’s not super friendly to most people and he’s kind of a weirdo himself.

But his main thing on the show was his massive crush on Rachel Green. Which never got returned. I think Gunther and Ross are kind of similar in the way that they lusted after Rachel like a pair of incels. But I think Gunther would have appreciated her and worshiped her forever as her boyfriend/ husband. Ross obviously and repeatedly took her for granted.

I am a little sad to learn that he passed away not long after the Friends Reunion special on HBO Max. Which was a reason he joined via video camera instead of appearing there in person.